Contractors have made moves to chop down a Norfolk Pine tree amid protests, north of Auckland.

Activist Charlie Cottrell-Jury climbed up the tree this morning - and had planned to stay overnight.

But he's now scrambled down to stop crews from killing the pine.

Police say the activist was arrested around 4.30pm and will be charged for trespassing. 

Locals were outraged when developers obtained a non-notified consent to axe the tree to make way for 30 houses.

Photos on social media show a cut in the trunk and it's understood police are in attendance.

The Norfolk Pine is believed to be more than 150 years old.

It is understood contractors will return first thing in the morning to finish felling the tree, after axing around its trunk this afternoon.

Mr Cottrell-Jury's hammock and supplies remain in the tree and will be collected tomorrow.